Mercury causes homosexuality in male ibises: Environmental pollutant radically changes birds’ mating behaviour

Nature journalYes, you read that headline right and no, this isn’t from The Onion. There are so many things that could be said about this…all I will say at this point is that I always enjoy a good laugh while reading the news. From the “international weekly journal of science “Nature“:

Exposure to mercury pollution could be hitting some wild birds’ reproductive prospects hard by causing males to pair with other males.

American white ibises (Eudocimus albus) from south Florida that consumed methylmercury (MeHg), the most toxic and easily absorbed form of mercury found in the environment, were more likely to engage in same-sex pairings — a phenomenon unknown in wild populations of this species with no exposure to the pollutant.

The main sources of mercury globally are coal-fired power plants and gold mining though in Florida, mercury was likely to have been released by the burning of medical and municipal waste. The metal is converted into methylmercury by some species of bacteria, usually found in wetlands that also tend to be home to many different bird species.

Peter Frederick, an ecologist at the University of Florida, Gainesville, and his colleagues collected 160 white ibis nestlings from breeding colonies in south Florida in 2005, and split them into four groups, each composed of 20 males and 20 females. Once the birds were 90 days old, the researchers began adding methylmercury to their feed. Three of the groups were given low, medium or high doses of mercury based on levels ranging from 0.05–0.3 parts per million recorded in the wild, while the fourth group were given no mercury.

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